Hurricane Harvey dumped more than twenty-seven trillion gallons of rain over Texas and Louisiana in six days. As of October 13, 2017, at least eighty-eight fatalities had been confirmed, most of which were drownings. Many locations in the Houston metropolitan area observed between thirty and fifty inches of precipitation; more than Houston usually receives in a year. Harvey was the wettest tropical cyclone on record for not only Texas but the United States; its toll, both emotional and economic, has been equally extreme. With such unprecedented rainfall, any city likely would have faced serious flooding problems, but was Houston in a more vulnerable position compared to other U.S. cities? Could legal codes, land use regulations, and zoning requirements have minimized some of Harvey’s devastation?
Houston is naturally prone to flooding; the city spans an extremely flat, low-lying part of the Gulf Coastal Plain — formerly forested land, marshes, swamp, and prairie — where clay-based soils provide poor drainage. The flood of 1935 moved local Houston authorities to petition the State of Texas to form a flood authority, and the Harris County Flood Control District (“HCFCD”) was born. For the next 60 years, the HCFCD, in unison with the U.S. Army Corps of Engineers, modernized Houston’s drainage system by building canals, widening bayous, creating concrete-lined waterways, and building reservoirs.
These efforts only partly succeeded, but flooding did not slow Houston’s growth. The area saw a population explosion of forty-two percent between 1995 and 2015. By comparison, the population of the United States has grown by about fifteen percent since 2000. Harris County, which encompasses Houston, added more people than any other U.S. county for eight straight years until 2016, when it fell to second. Recently, however, flooding has once again become a serious concern in Houston: in the years before Harvey, Houston’s Memorial Day Flood of 2015 took seven lives and caused $459.8 million in property damage, and Houston’s April 18, 2016 “Tax Day Floods,” resulted in eight deaths and caused $452.6 million in property damage losses.
Houston’s meteoric growth over the past two decades was accompanied by a construction boom. In 2014, Houston was third on the Forbes list of “Cities with Most New Constructions.” From January 2011 through December 2016, more than $90 billion in commercial, industrial, and residential contracts were awarded. With increased urbanization and development, Harris County has lost almost thirty percent of its freshwater wetlands. This loss has hindered Houston’s flood mitigation efforts because, wetlands slow, contain, store, and filter flood waters. When floodplain wetlands are allowed to function properly (and are not drained or impounded), floodwaters spread, reducing the velocity of flowing water and allowing time for water to slowly seep into the ground or be filtered by vegetation and sediment before flowing into rivers and bayous. Wetlands can hold water for days or even weeks, unlike paved surfaces or landscaped space, which release water in a matter of minutes or hours.
Coastal wetlands further serve as storm surge protectors when hurricanes or tropical storms come ashore. In the Gulf Coast area especially, barrier islands, shoals, marshes, forested wetlands, and other features of the coastal landscape serve as an important buffer from wind–wave action and storm surge. The Houston area formerly had acres of deeply rooted prairie grass, with a capacity to absorb water for days on end or even permanently. But most of that land has now been paved over. For example, recent development in the Katy Prairie northwest of Houston has reduced formerly flood-absorbing land acreage by three-quarters.
With the increasing severity of weather events, rapid growth, urbanization, and accompanying wetlands loss—it is perhaps not surprising that many articles have predicted flooding as Houston’s new norm. Even prior to Harvey, some questioned how Houston’s urban design and policy (or, impliedly, lack thereof) has contributed to worsening flood conditions and heightened human safety risks.
Houston expressly does not have formal zoning and is the only major U.S. city without a zoning code. Land use laws and zoning requirements can be effective ways to control and align development with overall flood mitigation policies. Every attempt to enact a zoning code in Houston has failed at the ballot. In 1948, voters rejected zoning by greater than a two-to-one margin. Similar ballot measures in 1962 and 1993 also failed. Houston does have ordinances, a building code, and other legal and governance mechanisms—including deed restrictions and historic designations—that allow homeowners in a neighborhood to impose rules that function as a sort of de facto, locally controlled zoning. These tools, however, are localized and fail to address flood mitigation on a regional level.
Also, it seems that not all Houston developers have followed the few rules in place. For example, to obtain a permit under the Clean Water Act, developers who build in protected wetland areas must submit paperwork showing completed mitigation measures. In 2015, a Texas A&M study analyzed a sample of permits issued from 1990 to 2012 in the greater Houston area and found that developers had submitted complete paperwork in fewer than half of the cases; in two-thirds of the cases, there was no documentation that any type of mitigation occurred.
Houston’s fast-track regulations that turn undeveloped land into developed land (platting) have contributed to Houston’s economic growth and conversely Houston’s lack of natural environmental protection. Enforceable private deed restrictions have been at the heart of Houston’s private regulation for decades. Such restrictions have allowed homeowners to control their neighborhoods, and businesses in designated urban districts to band together to influence development. If Harris County and/or Houston had substantive land use laws or zoning requirements, development could have been curtailed or harmonized with an overall master plan contemplating flood mitigation policies for the entire county.
The group Residents Against Flooding (“RAF”) believes that the City of Houston is a root cause of disastrous flood events. On May 25, 2016, RAF and six other plaintiffs filed suit against numerous defendants, including the City of Houston, alleging that government action has benefited private developers at the expense of Houston residents. The case is now on appeal following the defendants’ successful motions to dismiss, but the factual allegations of pending disaster contained in the lawsuit seem eerily prescient post-Harvey.
Outside the courts, partisan positons are being taken on the issue of whether stricter zoning rules, planning, or land use regulations could have saved Houston from Harvey’s devastation. Supporters of Houston’s no-zoning policy argue that Harvey was such a record-breaking storm that no amount of regulation would have made a difference.
Others contend that unrestricted construction exacerbated Harvey’s destructiveness, or that land use regulations could have been enacted specifically to prohibit development in floodplains, thereby lessening the habitable area affected by flooding and providing a collection area for much of the floodwater. Accounts from both camps vary in their reliance on hard data and tendencies for hyperbole. But with over a hundred people dead in the Houston area in the last two-and-a-half years as a result of flooding, maybe the time for partisan debate is over. The issue for Houstonians now, and really all Americans, as so much taxpayer money is at stake, is what to do going forward. Should it choose, Houston has a variety of planning roadmaps and best practices to choose from, developed by both national and international authorities.
FEMA, the very entity that has to deal with the aftermath of flooding disasters, recommends incorporating flood mitigation in local planning and opines that “[c]omprehensive planning and floodplain management can mitigate flooding by influencing development.” FEMA’s recommended strategies for local governments include incorporating floodplain and coastal zone management in comprehensive planning, developing a floodplain management plan, establishing a “green infrastructure” program to link, manage, and expand existing parks, preserves, and greenways, and obtaining rights to privately-owned land for temporary water retention and drainage. FEMA also recommends that development be limited or restricted in floodplain areas through regulatory and/or incentive based measures and that the International Building Code (“IBC”), the International Residential Code (“IRC”), and ASCE 24-05 Flood Resistant Design and Construction be adopted. In fact, FEMA lists twenty-three categories of policies/strategies for municipalities to prevent or at least mitigate flood damage.
International studies also identify land use strategies as an essential part of municipal flood prevention. For example, the 2003 European Union white paper, “Best Practices on Flood Prevention, Protection, and Mitigation,” recommends a good combination of structural measures, preventive measures, and operative measures during flood events, and further recommends that building codes and legislation be enacted to keep structures away from flood-prone areas. As regards land use and zoning, the paper specifically recommends that flood plains be identified and designated by law as priority sites for flood retention or to restore, as far as reasonable, mobility to waterways, and that development in the immediate areas at risk of floods or dam failures should be prohibited or severely restricted.
Seemingly, the authorities in the United States and in Europe both strongly recommend zoning and land use regulations in the battle against catastrophic flooding. Hopefully, Harvey can take Houston beyond discussions and lead to firm action.
First published on December 12, 2017 in “2 x 4 x 10” Winter 2017, ABA Forum on Construction Law, Division 10